====== auto versioning ======

If recipe points to not fixed version from git:

<code bash>
SRC_URI = "git://example.com/project.git;protocol=ssh;branch=${SRCBRANCH}"
SRCBRANCH = "devel"
SRCREV = "devel"
</code>

then version needs to be update for every change of source code.
To detect change automatically and prevent sstate errors:

<code bash>
SRCREV = "${AUTOREV}"
PV = "1.0+git"
</code>

To automatically increase package version number.